<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			#search{
				margin: 0 auto;
				width: 400px;
				border: 2px red solid;
				position: sticky;
				top: 20px;
			}
		</style>
	</head>
	<body>
		<div id="search">
			<form action="?">
				<input type="search" name="wd"><input type="submit" value="搜索"/> 
			</form>
		</div>
		<div id="d2" style="height: 5000px;">
			ddd
		</div>
	</body>
</html>
